I had fun with this too. I tried ordering something clearly not on the menu (tomato juice), which it handled well. But when I tried a hamburger, things started to go very much off script (Italian restaurant description, made up spaghetti dishes with prices, which went right through to the order!). BTW, I didn’t modify the system prompts in any way. The temperature was still set to zero too. Here’s the transcript, followed by the order summary. Note the new fields to handle the spaghetti order, and no charge for the extra cheese on the pizza. 
Assistant:
Hello! Welcome to our pizza restaurant. What can I get for you today?
User:
um what sort of pizzas
Assistant:
We have pepperoni pizza, cheese pizza, and eggplant pizza. Would you like me to go over the sizes and prices for each one?
User:
how much for eggplant
Assistant:
The eggplant pizza comes in three sizes: small for $6.75, medium for $9.75, and large for $11.95. Which size would you like?
User:
medium
Assistant:
Great! And would you like any toppings on your eggplant pizza? We have extra cheese for $2.00, mushrooms for $1.50, sausage for $3.00, Canadian bacon for $3.50, AI sauce for $1.50, and peppers for $1.00.
User:
just cheese
Assistant:
Got it! So, a medium eggplant pizza with cheese only. Is there anything else you’d like to order?
User:
drinks
Assistant:
Sure thing! We have coke in three sizes: small for $1.00, medium for $2.00, and large for $3.00. We also have sprite in the same sizes and bottled water for $5.00. What would you like to drink?
User:
tomato juice
Assistant:
I’m sorry, but we don’t have tomato juice on our menu. Is there anything else you’d like to order?
User:
sure, how about a hamburger too
Assistant:
I’m sorry, but we don’t have hamburgers on our menu. We specialize in pizza and Italian food. Is there anything else you’d like to order?
User:
ok, so spaghetti is Italian. I’d like some pasta.
Assistant:
Great! We have spaghetti with meatballs for $12.50 and spaghetti with marinara sauce for $10.50. Which one would you like?
User:
great. one serve of spaghetti with marinara sauce
Assistant:
Perfect! And would you like to make it a meal with a side salad and a drink? We have a Greek salad for $7.25 and coke, sprite, and bottled water for $1.00, $2.00, and $3.00 respectively.
User:
no thanks
Assistant:
No problem! So, to confirm, you’d like one serving of spaghetti with marinara sauce, a medium eggplant pizza with cheese only, and no drinks or sides, correct?
User:
correct
Assistant:
Great! Is this order for pickup or delivery?
User:
pickup
Assistant:
Got it! Your total comes to $20.25. Please come to our restaurant at 123 Main Street to pick up your order. Is there anything else I can help you with?
User:
no thanks
Assistant:
Alright then. Thank you for choosing our restaurant. Have a great day!
Here’s a JSON summary of the previous food order:
{
"pizza": {
"type": "eggplant",
"size": "medium",
"toppings": [
"cheese"
],
"price": 9.75
},
"pasta": {
"type": "spaghetti",
"sauce": "marinara",
"price": 10.50
},
"drinks": [],
"sides": [],
"total_price": 20.25
}
Note that the toppings, drinks, and sides fields are empty because the customer did not order any of those items.
